Originally Posted by
Indistinguishable Hmm... And you definitely have the 950XL added as one of your devices, right?
It did that on its own. I performed a hard reset in the meantime. Funny enough, I logged in with my Microsoft account during the setup process and it was accepted as usual. But as soon as WM10 was ready, there was no trace of that account anywhere. Outlook mail, calendar, store, Cortana... None were connected to my account. It was even missing from the account settings. And when trying to tap "login with your Microsoft account", nothing happened.
I'm currently performing another hard reset. I'm not giving up yet. ;)
[Edit]
That last hard reset fixed it. Yay! \o/